Abstract We have previously shown that nitric oxide (NO) induces differentiation and apoptosis in acute myeloid leukemia (AML) cells. Glutathione S-transferases (GST) are involved in multi-drug resistance and are upregulated in AML isolates. We have designed a class of diazeniumdiolate prodrugs that release NO upon interaction with glutathione in a reaction catalyzed by GST. Screening a library of these compounds with extensive lead optimization has led to the identification of O2-(2,4-Dinitrophenyl) 1-[(4- ethoxycarbonyl)piperazin-1-yl]diazen-1-ium-1,2-diolate or JS-K as the most active compound of this class. JS-K has shown potent anti-leukemic activity in vitro and in vivo. JS-K has challenging solubility properties. Preliminary pharmacologic studies have shown that JS-K reacts with blood components. The goal of this research project is the pre-clinical development of JS-K for the treatment of AML. For that purpose we will work on developing a nanoscale delivery system that will solubilize and stabilize JS-K in vivo. We will pursue the following aims: 1- Development of a micellar formulation for JS-K. Using Pluronics, we will develop a micellar formulation of JS-K aiming at enhancing its solubilization and decreasing its reactivity with blood components. 2- Study the pharmacologic properties of JS-K in a micellar formulation. Using micellar formulations developed in Aim 1, we will study the pharmacology of JS-K in mice. 3- Study the in vivo efficacy of a micellar formulation of JS-K in mouse leukemia models. Using the formulations developed in Aim 1, we will study the anti-leukemic properties of JS-K in vivo using AML xenograft models in NOD/SCID IL2R?null mice. At the completion of this work, we will have a workable formulation of JS-K for clinical development. This work will add to our armamentarium a new class of potent anti- leukemic agents. Narrative Relevance to public health: There is a great need for new drugs to treat Acute Myeloid Leukemia (AML). Work done in this project will develop a new drug called JS-K for the treatment of AML. This work will lead to great improvements in treatment of AML and other cancers.